From 332afa656e76458ee9cf0f0d123016a0658539e4 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 21 May 2012 16:58:01 -0700 Subject: [PATCH] x86/irq: Update irq_cfg domain unless the new affinity is a subset of the current domain Until now, irq_cfg domain is mostly static. Either all CPU's (used by flat mode) or one CPU (first CPU in the irq afffinity mask) to which irq is being migrated (this is used by the rest of apic modes). Upcoming x2apic cluster mode optimization patch allows the irq to be sent to any CPU in the x2apic cluster (if supported by the HW). So irq_cfg domain changes on the fly (depending on which CPU in the x2apic cluster is online). Instead of checking for any intersection between the new irq affinity mask and the current irq_cfg domain, check if the new irq affinity mask is a subset of the current irq_cfg domain. Otherwise proceed with updating the irq_cfg domain aswell as assigning vector's on all the CPUs specified in the new mask. This also cleans up a workaround in updating irq_cfg domain for legacy irq's that are handled by the IO-APIC. Signed-off-by: Suresh Siddha Cc: yinghai@kernel.org Cc: gorcunov@openvz.org Cc: agordeev@redhat.com Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1337644682-19854-1-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/io_apic.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index ac96561d1a99..910a3118438b 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1126,8 +1126,7 @@ __assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask) old_vector = cfg->vector; if (old_vector) { cpumask_and(tmp_mask, mask, cpu_online_mask); - cpumask_and(tmp_mask, cfg->domain, tmp_mask); - if (!cpumask_empty(tmp_mask)) { + if (cpumask_subset(tmp_mask, cfg->domain)) { free_cpumask_var(tmp_mask); return 0; } @@ -1141,6 +1140,11 @@ __assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask) apic->vector_allocation_domain(cpu, tmp_mask); + if (cpumask_subset(tmp_mask, cfg->domain)) { + free_cpumask_var(tmp_mask); + return 0; + } + vector = current_vector; offset = current_offset; next: @@ -1346,13 +1350,6 @@ static void setup_ioapic_irq(unsigned int irq, struct irq_cfg *cfg, if (!IO_APIC_IRQ(irq)) return; - /* - * For legacy irqs, cfg->domain starts with cpu 0 for legacy - * controllers like 8259. Now that IO-APIC can handle this irq, update - * the cfg->domain. - */ - if (irq < legacy_pic->nr_legacy_irqs && cpumask_test_cpu(0, cfg->domain)) - apic->vector_allocation_domain(0, cfg->domain); if (assign_irq_vector(irq, cfg, apic->target_cpus())) return;